Control of gloss may be critical in the design and application of protective and/or decorative coatings for many substrates such as, for example, leather, wood, glass, masonry, vinyl and vinyl composition flooring, linoleum flooring and walls.
In certain applications such as floor coatings, it is desirable to control gloss while maintaining a degree of protection for the substrate. In some instances, too much gloss is not a desired feature, such as in the case where senior managed care facilities are concerned. Glossy floors tend to be perceived as slippery (even though they are not) by elderly patients of the facility. Reducing the gloss of the coating without impacting slip resistance, while also maintaining a film for protection of the substrate, is desired.
One way to lower gloss has been to add matting agents, which are either inorganic particles, such as, for example, silica, or calcium carbonate particles, or organic particles, such as, for example, polyurethane dispersions, that function by roughening the surface of the film, or water dispersed acrylic acid dispersants which function to coagulate and disrupt film formation. While effective at reducing gloss, these matting particles often disrupt film integrity and can lead to loss of key film properties such as water and abrasion resistance, slip, etc. Still further, the matting particles tend to polish or burnish after rubbing, leading to an increase in the gloss over time. Inorganic matting particles also tend then to settle out of solution.
Others have unsuccessfully attempted to overcome the problems associated with the use of matting particles by controlling of particle size, minimizing random light scattering, careful selection of refractive index between particle and matrix, or modifying the matrix or film forming polymer. However, such approaches sacrifice clarity or film properties for matte effect and can greatly limit the scope of useful compositions.
For example, U.S. Patent Application Publication No. 2004/0062913 describes an aqueous- or solvent-based thermosetting resin composition comprising organic or inorganic porous fine particle matting particles which provides a jet black material forming synthetic leather articles which resist color fading. When used in coating or film compositions, such matting particles as described in U.S. 2004/0062913, have a propensity to produce films with impaired quality and flexibility, and even chalky or hazy appearance. Furthermore, where the system is solvent-based, unacceptable amounts of volatile organic compounds (VOC's) are present, which is undesirable from a health, environmental and safety standpoint.
International Patent Application Publication No. WO 2011/008631 describes polymer compositions that contain a gloss reducing agent and are useful in various finish compositions such as floor care compositions. The gloss reducing agent described in WO 2011/008631 includes polymer and a metal salt of a fatty acid, which are described as chemical compounds that include a hydrocarbon (i.e., monovalent hydrocarbyl) chain, a carboxylic acid, and an associated metal ion.
The present invention provides coating compositions having low gloss but without loss of other beneficial characteristics.